The present invention relates generally to window treatment apparatus, and more particularly to a shifting dual panel window shade.
Window treatments are well known. In addition to aesthetic features, window treatments also provide privacy, protection from sunlight, and thermal insulation. U.S. Pat. No. 58,688 discloses a double panel curtain window treatment, where a pair of panels 38, when extended, are spaced apart by a distance equal to the diameter of the roller 36, and wherein the two panels extend from the two different sides of the roller 36. The panels 38 are connected together along bottom portions thereof by tacking to a bottom bar v. Each of the panels 38 includes a series of aligned holes X. When the roller 36 is rotated a small amount, the alignment of the holes X changes, affecting the passage of light and air through the panels 38. One disadvantage of the ""688 patent is that dust and debris tends to accumulate within the relatively large space or opening formed between the two panels.
U.S. Pat. No. 2,280,358 discloses a pair of window shade panels 10, 14 disposed either on a single roller or on a pair of rollers, whereby a small movement of one panel relative to the other panel will act to exclude light wholly or partially. In one embodiment, the panels comprise polarized elements which block light when the panels are in register with each other. As the polarized portions are moved further apart from registration, the amount of light that passes through the panels changes. In another embodiment, alternate opaque and transparent strips or sheets are employed. An elastic strip 15 is provided on either one or both of the sheets so that the panel having the elastic strip can be moved relative to the other panel without rotating the rollers.
Prior art window treatments are relatively complicated in construction and operation, and have the additional disadvantages discussed above. A need exists for a simple, easy to manufacture dual panel window shade having the advantages of the present invention.
The objects and the advantages of the present invention include providing a dual panel window shade apparatus that offers an unlimited choice of prints and patterns that can be incorporated into the sheer panels. The disclosed apparatus provides selective privacy from all angles inside the home and out, and the panels can include large or small prints or patterns. The present apparatus can be manufactured with an enclosed canopy in a small scale headrail, and can be mounted with no light gap between the window frame and the panels. The present apparatus can be produced in room darkening models, and since the panels are not cellular, the designs will not collect debris. Also, the disclosed invention can be manufactured simply, with few moving parts.
Other objects and advantages of the present invention will be apparent from the following detailed description of the illustrated embodiment of the invention.
The present invention is directed to a dual panel window shade apparatus. The apparatus includes an outer panel, an inner panel, a cord, a canopy and a spool. The panels can be made, for example, from fabric, paper, vinyl or the like. The spool is mounted within the canopy for rotation relative thereto. The panels are radially spaced apart and rigidly attached at respective upper ends thereof to an outer surface of the spool.
In operation, the respective panels extend over a rigid contact and guide surface, such as an edge of the canopy, for example, and hang generally downward therefrom. The spool is selectively rotatable via the cord and a clutch mechanism to move the panels generally up and down relative to one another. For example, as one panel moves up, the other panel moves down, and vice versa. Changing the diameter of the spool effects the offset shift of the two panels.
In one embodiment, one of the panels has a positive of a design, and the other of the panels has a negative and, in the illustrated embodiment, slightly larger print of a similar or identical design thereon. For example, the outer panel may have opaque portions of the design on a surface thereof, with sheer or scrim portions between the opaque design wherein light can pass through the sheer or scrim portions. The inner panel correspondingly includes sheer or scrim portions in alignment with the opaque design on the outer panel, and opaque designs in alignment with the sheer or scrim designs on the outer panel. In operation, as the spool is rotated, the corresponding sheer and opaque design portions become offset with respect to one another, varying the amount of light which passes through the apparatus.